Process of forming grease-cups.



A. R. PRIBIL.

PROCESS OF FORMING GREASE CUPS.

APPLICATION FILED MAR. 1. 1912.

1 ,26 5 ,954; Pafented May 14, 1918.

FIG.l.

4' a5 a\ 1d 6411014101 6 UNITED STATES; PATENT onnron. Q.

name 3.. mm, or mirnorr, iurcmean, nssrenon, BY mnsnn nssremn'rs, 'roenonen w. rowan, or Amman, new Yonx.

PROCESS OF FORMING GREASE-CUPS.

Specification of Letters Patent.

Patented May 14, 1918.

Application filed March 1, 1912'. Serial No. 881,001.

following is a specification, reference being,

had therein to the accompanying drawings.

In forming grease cups and like artic es from sheet metal it isdesirable that the metal of the extended end or shank portion of the cupbe increased in thickness to give added strength and so that it may bescrew threaded without materially weakening the" part. It is alsodesirable that the thickness of the metal formin the body of the cup bemaintained so that t e cup will not be weakened at its angles and breakwhen a wrench is applied thereto. The object of this invention is toprovide a simple process of forming such articles from sheet metal,which process embodies but few steps in the operation and insures theforming of the article with a wall of the proper thickness. Theinvention consists generall in first applying pressure to the center 0 yof the blank, to force it into 1 a forming die with the whole body ofthe metal free to move inward and form around the forming punch, andthen applying pressure to a portion of the interior'of the partiallyformed article to force it into a finishing die and to contract andthicken the wall of that portion of the article to which internalpressure is not applied.

. In the drawings illustrating the several steps in the operation ofcarrying out the "process embodying the invention,

Fi re 1 is a vertical section through a punc and die for use in carryingout the process and showing the punch within the die and the blankpartially formed thereb Fig. 2 is a similar view of a finishing ie withthe partially formed blank. in place in the die and a broach or male diein position to enter the same;

. Fig. 3 is a view similar to Fig. 2 showing the parts in position atthe en eration and the formed cup in place in the die; and

'Fig. 4 is a side elevation of the formed on detached.

his process of pressing single-piece grease cup bases from flat metalblanks consists in applying pressure to one side only of the opof thecentral art of the blank and to the opposite side 0 the outer part ofthe blank I and thereby forming at said central part a hollowelongated-projection extending axis ally from said surrounding partofthe blank, applymgpressure to opposite sides of the outer art of theblank by opposing cir- V cular sur aces of truncated conical form havingtheir radii arranged at an obtuse angle to the lon 'tudinal, axis of thehollow. pro ection and-t us forming the outer part of the blank into atruncated conical rim extending laterally from the base of the pro-'ection, supporting the blank on the inter1or surface of the inner partof the rim and applying pressure tothe exterior surface only of thehollow projection and thereby reducin the diameter of the projection andthickenmg its wall, applying pressureto the exterior and interiorsurfaces of the outer part of said rim and thereby forming said i. outerpart into a cylindrical marginal flange having its longitudinal axiscoincident with the longitudinal axis of said projection, applyingpressure' from the interior of the projection outwardly and also againstthe exterior of the projection near the base thereof for forming thesame into a hollow hexagonal shape, and applying pressure to theexterior and interior surfaces of the blank between the cylindricalflange and the base of the projection.

A disk or blank of the proper size to form a grease cup is cut from asheet of brass, steel or other suitable metal of the desired thickness,by means of a blanking die 1 and a sleeve punch 2 which is forceddownward into the blanking die by ower applied to its upper end andsevere a, sk or blank 3 of metal from the sheet.

As a convenient means for carr 'ng out the process of formin this blanli into a rease cup, a forming dle 4 is provided withm the blanking die1, and the blank when severed falls upon this forming die in position tobe engaged at its center by a tapered axial extension or finger 6 on thelower end of a forming punch 5which is reciprocable within the sleeve 2.The forming die is formed with an axial opening 7 and with an upper endforming surface 8 inclined downwardly toward said opening. The finger 6of the terrain punch enters the openmg 7 in the die wit a space betweenit and the thickness of the metal of the blank, and the lower end of theforming punch is formed with an inclined surface or comcal end corresonding to the incline of the surface 8 of t e die.

The finger 6 of the forming punch thus engages the blank at its centerwhen force is applied to the upper end of the punch to move it into thedie, and the blank is forced downward into the die with the body of theblank free tomove inward and form around the punch and its projectingfinger. As the body of the metal is not hel by the punch or d1e, saidmetal is not drawn but is formed or swaged into shape by the action ofthe punch and its thickness is determined by the space between thesurface of the punch 5 and the surface of the die. This operation ofappl ing pressure to the center of the blank to orm it over the end ofthe forming punch constitutes the first step in the process embodyingthe invention.

A post or broach 15 is provided to enter a finishing die 10 and its bodyis just enough less in diameter than the internal diameter of the outerend of said die so that the projecting edge portion of the conical part9 of the partially formed blank when laced upon the broach, with saidconiea part resting upon a conical upper end of the broach, will be bentand formed downward around said body of the broach without stretchin ordrawing the metal to any great extent but with a, compresslng orforming-in action. The broach is formed with a hexagonal or otherangular end portion 16 integral with its conical end at the axis thereofto enter the member 11 of the die and form the portion 12 of the cupoutward therein. This part 16 of the broach is not long enough to enterthe inner portion 13 of the chamber of the die and therefore when theblank is forced into the die by the broach, the metal of the end portion14 of the cup is free to compress and being limited in diameter andlength by the walls of said chamber, the end an side walls of said endortion 14 of the cup are materially thickene Such compression of thesewalls causes ribs to form upon the inner surface thereof, thus greatlyincreasing the strength of the art as well'as providing ample thicknessor cutting a screw-thread thereon. This operation of applying pressureto the interior of a portion of the partially formed blank to press orform that portion of the same outwardly into a finishing die and therebyforce the.

mteriorly unengaged' portion into the die to compress the metal,constitutes the second step in the process.

In both steps of the process, the metal is bent and formed or swagedinto shape, as distinguished from being stretched or drawn, and thus itsthickness 1s maintained in all parts of the body to give the desiredstrength to all angles, and by compressing the metal a forming otherportions, the wall is thickened. A minimum of power is required to formcups by this process as very much less power is required to bend andswage metal than to draw it.

Having thus fully described the process embodying the invention and themanner of carrying out such process, what I claim is 1. Theherein-described process of pressin single-piece grease-cup bases fromflat sheet-metal blanks, the same consisting in applying pressure to oneside only of the central part of the blank and to the opposite side of apart of the blank surrounding said central part and thereby forming acentral hollow elongated projection extendin axially from saidsurrounding part 0 the blank, applying pressure to opposite sides of the'outer part of the blank by opposing circular surfaces having theirradii arranged at an angle to the longitudinal axis of the hollowprojection, and thus for a circumferential rim extending laterally fromthe base of the projection, suppo the blank on the interior surface ofthe inner part of the rim, and applying pressure tothe exterior surfaceonl of the hollow projection and thereby re ucing its diameter andthickening its wall, applying pressure to the exterior and interiorsurfaces of the outer art of the circumferential rim and thereby florminsaid outer part into a cylindrical ange dent with the longitudinal axisof said projection, and applyin pressure from the interior of the baseof t e projection outwardly and also against the exterior of the base ofsaid projection for form' said base into a hollow hexagonal shape sostantially as and for the purpose described.

2. The herein-described process of pressing single-piece ease-cup basesfrom flat sheet-metal blan the same consisting in applying pressure toone side only of the central part of the blank andto the opposite sideof the outer part of the blank and thereby forming at such central parta hollow elongated projection extend' axially of the blank from saidopposite si e of the outer part of the blank, applying pressure to o 0-site sides of the outer part of the blank y opposing circular surfacesof truncated conical form having their radii arranged at an obtuse angleto the longitudinal axis of the hollow projection, and thus forming theouter part of the blank into a truncated conical rim extending laterallyfrom the base of the projection, supporting the blank on the interiorsurface of the inner part of the rim and applying pressure to theexterior surface 0 y of the hollow rojection and thereby reducing itsdiameter and thickening its wall, applying pressure to the exterior andnterior surfaces of the outer part of said rim and thereby forming sa'douter part into faces of the blank between the cylindrical 19 p I acylindrical flange havinfi its longitudinal. flange and the base of theprojection, subaxis coincident with the ongitudinal axis stantially asand for the purpose set forth. of said projection, applying pressurefrom In testimony whereof I aflix my signature 5 the interlorof theprojection outwardly and in presence of two witnesses.-

also a inst the exterior of the projection v ALEXIS R. PRIBIL. near ebase thereof for forming the same Witnesses: into a hollow hexagonalshape, an applying Ann M. Donn, pressure to the exterior and interiorsur- LEWIS E. Fmmmns.

